This invention relates to a method and system for processing image data from an item, like a document, for example, and also for producing a compressed, binarized version of the image data for transmission to or use by subsequent users. In particular, it relates to a method and system for compressing data in a multi-channel image processing system.
In some financial systems, for example, documents, like checks and deposit slips, are scanned by an imager as the documents are moved along a document track by a document transport means. In general, the imager scans along a single scanning line as the document is moved past the imager. With this system, there may be 640 "pixels" or picture elements, for example, in a single scan, depending upon the size and resolution requirements of the system.
A pixel represents image data coming from a portion of the document at the scanning line. The pixel coming from the scanning line is generally an analog signal; however, it is converted, typically, to an eight bit byte of data by an analog/digital converter for further processing by the system. Successive scans of data are obtained as the document is moved past the imager.
The pixel data coming from imaging a document, as described, may be used, for example, to generate an image of the document on a video display or CRT. When so displayed, an operator viewing the image may perform data completion, for example, by entering the monetary amount, etc. (associated with the document) on a keyboard which is part of the financial system.
In recent years, efforts have been made to increase the throughput of documents by reducing the time required to process the image data.